The ability of cells to react appropriately to nutritional cues is of fundamental importance, and in budding yeast, a small number of intracellular protein kinases, PKA, Snf1p/AMP-activated kinase, TOR, Gcn2p, and the cyclin-dependent kinase Pho85p have key roles. A recently characterized enzyme, PAS kinase, may be a new member of this group of nutritional transducers.